From Mapassembly

What is MAP?

MAP is an acronym for Map Assembly Project. Goal of this project is to create a
street map which can freely be used by anyone, mainly by other Open
Source projects, which can use the data to create a navigation system
or whatever.

You need to download the latest MAPEditor to contribute to the MAP. The current version is 0.7.0 (ReadMe.txt, changelog.txt), released on Febuary 23, 2007. Look at the wiki manual for help on using the MAPEditor.